Astronomers at the McDonald Observatory in Fort Davis, Texas are on the verge of a major discovery after capturing light from galaxies 10 billion to 12 billion light-years away — more distant than any dark energy survey has attempted before. The Hobby-Eberly Telescope, with its 91 hexagonal mirrors and 156 spectrographs, collected data from 2017 to 2024 as part of the HETDEX project.

The work was only possible because of the Greater Big Bend International Dark Sky Reserve, the largest such reserve on Earth spanning over nine million acres across Texas and Mexico. Designated in 2022, the reserve's strict lighting ordinances protect the darkness that scientists need to detect photons so faint that even a full moon would wash them out.

"Dark energy is the phrase we use to represent our ignorance of how the universe is expanding," said Karl Gebhardt, the University of Texas at Austin astronomer leading HETDEX. The team is mapping the early universe's structure from an era roughly two billion years after the Big Bang, when dark energy first began accelerating cosmic expansion. The findings could reveal whether the universe eventually tears itself apart.

Beyond science, the dark skies have created an ecosystem of star parties, dark-sky tourism and economic opportunity in one of America's most rural regions. Nearly 400 visitors attended a recent star party during International Dark Sky Week.